Dysarthria is a common motor speech disorder following acquired neurologic conditions such as stroke and traumatic brain injury (TBI). Dysarthria is a major source of disability as it causes difficulty with communication and poses significant barriers to employment and re-integration into the home and community. Individuals with dysarthria require extensive speech practice over time in order for motor learning to occur to improve their ability to communicate. However, there is limited financial support for speech therapy to provide individuals with dysarthria the extensive speech practice opportunities required to regain functional speech for productive participation in work, home and community settings. Thus, it is critical that more effective approaches be developed to support and supplement the limited speech therapy services individuals with dysarthria receive. This study furthers the mission of the NCMRR/NICHD to enhance the independence and well-being of persons with disability through rehabilitation by developing a novel approach to speech practice for dysarthria using the Supplemented Speech Recognition (SSR) program. The SSR has been developed by the research team and utilizes speech recognition technology that can manage severely dysarthric speech as an assistive writing program. This investigation will provide the preliminary data to support the future development of the SSR into a computerized speech practice system. Aim 1 will focus on developing the technical ability to acoustically manipulate dysarthric speech samples to provide a practice model. Specifically, this project will manipulate the speech productions of individuals with moderate to severe dysarthria by replacing distorted or omitted consonant phonemes with typical gender-matched, typical age/gender-matched, and synthetic gender-matched samples. Aim 2 will identify the recognition accuracy of the SSR with manipulated speech samples. The PIs hypothesize that the different manipulation strategies will yield comparable recognition accuracy results due to their experience with its ability to recognize severely distorted as well as non-distorted speech. The result of this will drive the future direction of the development team by identifying which manipulation strategy to focus on to produce functional speech practice targets to develop the SSR into a speech practice tool. Finally, Aim 3 will document the preliminary changes in speech performance across 15 trial therapy sessions to identify the potential role of SSR in long-term speech practice. The PIs hypothesize that individuals with moderate to severe dysarthria will demonstrate increases in speech intelligibility of target practice words and that their speech productions will change acoustically while using the SSR compared to their habitual productions. This study will utilize a three-level research design that includes molar (group analysis using a within subjects repeated measures ANOVA), intermediate, and molecular (individual detailed case studies) levels of analysis. Achievement of the aims of this project will lay the groundwork for the development of a computer practice program that automates the speech stimuli manipulations for functional speech practice. PUBLIC HEALTH RELEVANCE: Individuals with speech impairment (dysarthria) due to traumatic brain injury (TBI), stroke, and other neurologic conditions require extensive amounts of speech practice in order to recover functional communication abilities to participate fully in work, home, and community settings. However, due to challenges with reimbursement for speech therapy services, support for extensive and long-term speech practice is limited. New intervention strategies that augment traditional speech therapy services and support continuous, long-term speech practice are needed. This project will provide the preliminary data for the development of a computer-based speech practice tool designed specifically to support extensive and long-term speech practice for individuals with moderate to severe dysarthria.